Clinching the Pacific diver at Caolas beag, Gairloch

I'm not sure that it needed clinching, but I needed more views to be certain in my mind. The problem was, on Saturday I'd seen the Pacific diver and it was perfect. Small size, dark flanks, grey cheeks and small fine bill. It was so different to the accompanying black-throated divers that it looked more like a grebe than a diver. I was completely happy that I was watching a Pacific diver, though I didn't see the chin strap or the vent strap. 

However, then I went back on Sunday and saw what I thought at first was the same bird, but the jizz didn't seem right. Features that had looked so good on Saturday now looked uncertain or even wrong, and it was especially missing the grebe like appearance. Then it rolled onto it's side..... no vent strap. At this point I should say that I was watching the bird at 750m distance, so picking up on jizz is difficult as are small plumage details and things like bill size. But if it was a Pacific diver I should have been able to see the vent strap. 

Then there was a further complication which clouded my judgement. Up until this point everybody had told me that the Pacific diver was currently the only winter plumage diver in this area, and as if to confirm this, all of the black-throated divers I had seen so far were in summer plumage. I was still convinced that I had seen the correct bird on Saturday, but Sundays bird looked like a black-throated to me. Had I got it wrong on Saturday? Was I wrong on Sunday? Or where there actually two birds? I needed more views or I would forever doubt myself.

With a whale watching trip booked from Gairloch this afternoon leaving me with a free morning, it seemed like a good opportunity to head back to Big Sand and make the most of the flat calm conditions to hopefully get better views of the Pacific diver. Instead of wasting time at the burn mouth near the campsite at Sands, which is simply too far away, I headed immediately along the rocky shore to a headland about a 1.5km to the north west and scanned from there. 

It took me a while to find the flock of 17 black-throated divers because they were close to the island well over 1.5km away, but soon they drifted my way. Almost immediately I spotted a winter plumage diver with them and excitedly took some video, but no matter how hard I tried, it still didn't seem right and after watching for a while I could only conclude that it was an adult winter black-throated. It just wasn't a Pacific diver.

Pacific diver. Note the rounded head shape,
small bill, grey cheeks & complete chin strap. Also
the fuller hind neck giving the bird a distinctive jizz.

This was crushing and I was at the point of giving up, totally depressed because I felt this now left my Saturday sighting in tatters. I must have made a mistake, I was no longer convinced that I had seen the Pacific diver at any time, and frankly I was even beginning to doubt that there had ever been one at Caolas beag. After all, hadn't I been told that there was only one winter plumage diver here? I had one last scan over the sea.

Pacific and black-throated divers. Pacific
 can be up to 20% smaller than black-throated,
 and you can really see the difference in this photo.

Amazingly within a minute I picked up a second winter plumage diver and knew instantly that it was the Pacific. It's whole jizz was so different. It was a long way out, probably 1km, but it was with a summer plumage black-throated and the difference was stark. This was no indecisive "is it or isn't it?" moment, this was a slap-bang in the face "That's it!" moment. I did a little dance on the spot, but thankfully there was nobody to see, just a few bemused and slightly nervous sheep.

Pacific diver with black-throated. Note the
difference in head size & shape as well as bill size.

The two divers made their way slowly towards the larger group and eventually joined up with them and were now about 500m away from me. Apart from all of the other identification features I have so far mentioned, I could now also see the chin strap. This was more like it!

Best of all, I was thrilled to see that the impression I had got on Saturday was correct, this bird did indeed look like a grebe in amongst the divers. My photos even capture that impression perfectly, just as those taken by Tor Olson did of a bird in Norway in 2015, which I included in my post on Saturday.

Finally it rolled onto it's side and preened, revealing it's vent strap! Perfect. Colin's finally happy that it's a Pacific diver. Hallelujah! Now we can all sleep easy.....

The chin strap really stands out.

Pacific diver. All of these photos show dark flanks.

Pacific diver. Note the fine, almost
red-throated diver like bill & grey cheeks.

Pacific diver, left, and winter plumaged
 black-throated diver, right. 

These birds were about 700m away and the photos were taken on my phone, through my scope. The scope was on 60x magnification and my phone camera on 5x optical zoom. I took a few videos and then when I watched them back I took video grabs to create these images. I then cropped the images to remove the vignetting. Therefore these photos will be approximately 500x magnification or more (60 x 5 x crop). So though they might seem very poor images, I think they're actually outstanding! 

Even at this distance and at very high magnification, you can see that the winter plumage black-throated diver, the middle bird, is larger with white cheeks and white flanks. The Pacific diver on the right has grey cheeks and a finer bill.

Winter plumage black-throated diver.

Looking across Loch Gairloch towards to Torridon mountains. Not a bad place for a few hours watching divers.

Keep calm sheep....

I love this building. Look at the anchor leaning against the wall.

I feel a great connection with my Dad on a day like today. He loved this area and first brought me here in 1979, and we came, specifically looking for divers. I wouldn't call myself an expert at anything, but I'll put myself up against anybody when it comes to identifying divers in any plumage and all those years of experience with my Dad pay dividends on a day like today. This Pacific diver has proved a great learning experience for me. It's not so much that I'm an expert with Pacific diver, clearly I'm not, this was only my second ever, but I do know my black-throated, red-throated and great northern very well. Subtilties of plumage and jizz are all obvious to me, even at distance and in difficult viewing conditions, making the Pacific diver stand out like a beacon. As with all things birding, if you know your commoner stuff well, it makes identifying the rarities easier. 

Longa Island and Caolas beag.

The morning rounded off nicely with a celebratory pint of the local brew (and some fish and chips which are off camera 😆).

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